The primary objective of this registry will be to characterize the clinical and laboratory course of severe congential alpha1- antitrypsin deficiency whether or not the patient is undergoing long-term replacement therapy. Severe congenital alpha1-antitrypsin is associated with the early onset of emphysema, usually by the third decade of life. One approach to correct this deficiency is through replacement with alpha1-antitrypsin (referred to as alpha1-proteinase (A1 Pi) inhibitor in its purified form). There currently is no data base available for estimating the degree of clinical benefit if any of A1 Pi. The slow progression of emphysema and lack of an adequate control group have made it difficult to evaluate the proteinase inhibitor through a controlled clinical trial. A registry is an alternative to collect data on the effect of long- term replacement therapy with A1 Pi on rate of decline of lung function. The registry will also include individuals who are not receiving the replacement therapy in order to obtain a better knowledge of the rate of decline of lung function associated with the congenital deficiency for alpha1-antitrypsin.